The present invention relates to a polycaprolactone custom dental tray and a method of making said tray.
A dental tray is a receptacle that is used to carry a material such as, impression, bleaching or fluoride, to the mouth. Its purpose is to confine the material in apposition to the surfaces of oral anatomy to be recorded or affected, and to control and confine that material while it sets or performs its function. There are two basic types--stock dental and custom dental trays. Stock dental trays are trays that have been prefabricated by a manufacturer in a variety of sizes that would closely approximate the anatomy of a wide grouping of people. They are available in standard sizes of small, medium and large. They are used only for preliminary procedures and produce preliminary gypsum models of the teeth and surrounding structures.
Custom dental trays are trays that are made by the dentist or dental laboratory on preliminary gypsum models and are designed to enable the dentist to make a more accurate and detailed impression, or treatment than is possible with stock trays. Custom dental trays are fabricated for a specific procedure, for one person, and are precisely made to that one person's individual oral anatomy. They are discarded after use.
One of the techniques used to fabricate custom dental trays is to first form a preliminary gypsum model with a stock dental tray. Preformed flat sheets of a shellac composition or a thermoplastic are placed on a gypsum model and heated to a soft, deformable, adaptable state. The softened sheet is then pressure formed to conform to the gypsum model. This method produces an excess of material overlapping the model and requires substantial finishing, grinding and polishing. The shellac material is also brittle when hardened and subject to fracture in the mouth when being used as a custom dental tray.
A variation of the above method is known from U.S. Pat. No. 4,401,616. In U.S. Pat. No. 4,401,616 a custom dental tray is made by using a thermoplastic flat uniform thickness sheet which is manually bent over the gypsum cast. The thermoplastic sheet is made of Polyform. The chemical make-up of Polyform was not disclosed. However, the use sheet material requires extensive trimming and cutting.
U.S. Pat. No. 4,569,342 teaches a variation of the above method. A stock tray is made of thermoplastic material i.e. methylmethacrylate, heated so as to soften, and then remanipulated and reshaped according to the biting surfaces of the patient. The tray requires extensive trimming.
The Tone polymer literature distributed by Union Carbide states that poly caprolactone polymers may be mixed with various polymers and may be utilized as orthopedic casts; plaster replacement; controlled release matrix; as an adhesive when combined with other polymers; a mold release characteristic when added to polycarbonate; poly (butylene terephthalate)--fiberglass and the like; a pigment dispersant; in biodegradable systems; shoe counters; do it yourself toy or hobby applications; and synthetic wound dressings. The Tone literature does not discuss nor suggest the use of polycaprolactone polymers for custom dental trays.
In all cases the current technology and materials available for the fabrication of custom dental trays are dependent upon a preformed-form of one sort or another that is readaptable or readjustable. This denies the dental professional the freedom of true individualized custom molding capabilities for each patient. Each of the prior art methods also produces an excess of material circumferencially around the periphery of the tray. This excess must be trimmed through grinding, shearing and polishing to prevent irritation and effectuate a correct fit. This is a time consuming and messy process. The present invention provides a method for making custom dental trays that is not dependent on or limited to the confines or restrictions of a preform. The present invention instead offers true freedom to the dentist of a wide and unlimited variety of geometric configurations to suit individual patients without limit to size or shape. Further, my method can even be used in veterinary dentistry. That is on the odd, difficult and differing shapes of equine, feline and canine oral anatomies.
My method for making custom dental trays substantially limits any excess over extensions of material at the periphery of the model and substantially reduces any trimming, grinding, shearing, polishing and smoothing. This saves time and expense to both patient and dentist.
Therefore it is an object of the present invention to provide a simplified method of preparing a custom dental tray by the dentist in his office.
It is another object of the present invention to provide a method of preparing a custom dental tray without utilizing extensive trimming, cutting and polishing of the custom dental tray.
It is another object of the present invention to provide a custom dental tray by placing a quantity of thermoplastic aggregate i.e. beads, pellets, powder or granules in a container of hot water which is at a temperature of about 140.degree. F. to boiling; the thermoplastic material remains in the water until it forms a soft pliable conglomerate or non-descript mass of thermoplastic; the soft pliable thermoplastic mass is removed from the hot water; manually working the soft pliable thermoplastic into a pliable usable shape; covering only the teeth and/or gingiva of a dental cast, i.e. confined within the periphery; maintaining the thermoplastic on the cast until the thermoplastic hardens and cools to substantially room temperature; removing the hardened room temperature thermoplastic from the cast and submerging the room temperature cast in cold water having a temperature of from about 40.degree. F. to about 60.degree. F. for at least about 30 seconds to form a hardened custom dental tray.
Still another object of the present invention is to use an organic thermoplastic material to prepare the custom dental tray wherein the thermoplastic material contains at least about 75% by weight of a polycaprolactone of the formula ##STR1## wherein R is an aliphatic group, and n is 300 to 650 and preferably has an average molecular weight of from about 35,000 to about 60,000 and a crystalline melting point of from about 120.degree. F. to about 150.degree. F.
Still another object of the present invention is to provide a polycaprolactone custom dental tray.
A still further object of the present invention is to provide a polycaprolactone custom dental tray wherein the polycaprolactone has the formula ##STR2## wherein R is an aliphatic group, and n is 300 to 650 and preferably has a molecular weight of about 35,000 to about 60,000 and a crystalline melting point of from about 120.degree. F. to about 160.degree. F. and preferably from about 130.degree. F. to about 150.degree. F.